The present disclosure relates to systems and methods for detecting fixation frame parameters. More particularly, the present disclosure relates to systems and methods that facilitate medical personnel in determining whether, and the extent to which, a fixation frame adjustment is proceeding according to a correction schedule.
The external fixation market may be generally divided into two segments: acute trauma and reconstructive. The trauma segment may include modular fixators, which may be characterized by limited componentry and rapid application. Consequently, they are known for being fairly simple products. Many of these frames are used for temporizing fixation and may only be on the patient for hours or days. The reconstructive segment generally leans toward ring fixation. Examples of ring fixators are shown in U.S. Pat. Nos. 4,365,624, 4,615,338, 4,978,348, 5,702,389, and 5,971,984. Their use of a combination of pins and wires to achieve a variety of polyaxial pin/wire attachments may provide stability. They can accomplish a full six degrees of freedom and can correct primary deformities without creating secondary deformities.
It is sometimes necessary to realign, reposition and/or securely hold two bone elements relative to one another. For example, in the practice of medicine, bone fragments and the like sometimes are aligned or realigned and repositioned to restore boney continuity and skeletal function. At times, this may be accomplished by sudden maneuver, sometimes followed by skeletal stabilization with cast, plate and screws, intramedullary devices, or external skeletal fixators.
A bone fragment can be moved, in general, from its original position as in a nonunion or malunion or from its intended position as in congenital deformities along six separate movements or degrees of freedom, a combination of three orthogonal translational axes (e.g., typical “X,” “Y” and “Z” axes) and three orthogonal rotational axes (e.g., rotation about such typical “X,” “Y” and “Z” axes).
External fixation devices may be attached to the boney skeleton with threaded and/or smooth pins and/or threaded and/or smooth and/or beaded wires. Such constructs are commonly referred to as orthopaedic external fixators or external skeletal fixators. External fixators may be utilized to treat acute fractures of the skeleton, soft tissue injuries, delayed union of the skeleton when bones are slow to heal, nonunion of the skeleton when bones have not healed, malunion whereby broken or fractures bones have healed in a malposition, congenital deformities whereby bones develop a malposition, and bone lengthening, widening, or twisting.
A circumferential external fixator system was disclosed by G. A. Ilizarov during the early 1950s. The Ilizarov system includes at least two rings or “halos” that encircle a patient's body member (e.g., a patient's leg), connecting rods extending between the two rings, transfixation pins that extend through the patient's boney structure, and connectors for connecting the transfixation pins to the rings.
Often orthopaedic external fixators such as Ilizarov fixators must be repositioned after their initial application. Such modification may be necessary to convert from one correctional axis to another or to convert from an initial adjustment type of fixator to a weight bearing type of fixator, some of the correctional configurations not being stable enough for weight bearing.
External fixators may be adjusted over a period of time to reposition bone segments. The adjustment of the external fixation may be implemented according to a “prescription” or correction plan. Physicians may adjust the external fixator at precise times over a period of time (e.g, on a daily basis for three weeks). Patients, however, may not desire to visit the physician's office every time an adjustment is needed. For this reason, many external fixators can be adjusted by the patients themselves without the assistance of a physician. The adjustment of the external fixator should nonetheless strictly comply with the predetermined correction plan. In some occasions, patients may not adjust their own external fixator according to the correction plan for a variety of reasons. For instance, patients may not understand how to use the external fixator correctly. In addition, when the patients themselves adjust the external fixators, physicians may not even know whether patients are in fact adjusting the external fixators according to the correction plan. For the foregoing reasons, it is desirable to provide systems and methods to detect fixation frame parameters to allow determination of whether the adjustment is proceeding according to plan.